You should use group boxes to group the radio buttons, that should stop the black dot from jumping between groups. To set the radio button to checked you can use:
Code:
SendMessage(hWnd, BM_SETCHECK, BST_CHECKED, 0);
Here is some info on BM_SETCHECK
An application sends a BM_SETCHECK message to set the check state of a radio button or check box.
BM_SETCHECK
wParam = (WPARAM) fCheck; // check state
lParam = 0; // not used; must be zero
Parameters
fCheck
Value of wParam. Specifies the check state. This parameter can be one of the following values:
Value Meaning
BST_CHECKED Sets the button state to checked.
BST_INDETERMINATE Sets the button state to grayed, indicating an indeterminate state. Use this value only if the button has the BS_3STATE or BS_AUTO3STATE style.
BST_UNCHECKED Sets the button state to unchecked
Return Values
This message always returns zero.
Remarks
The BM_SETCHECK message has no effect on push buttons.
- Sean
